Group A Streptococcal Pyomyositis in a Previously Healthy Six-year-old Girl

A six-year-old previously healthy girl was seen in an outpatient pediatric clinic in the western United States for thigh pain. The pain was accompanied by an initial fever and was most severe after periods of prolonged rest. During the evaluation, her exam rapidly progressed with severe episodic pain and tenderness of the right anteromedial thigh. Magnetic resonance imaging (MRI) demonstrated signal enhancement at the insertion of the right obturator externus muscle. Blood culture was positive for Group A Streptococcus. She was diagnosed with pyomyositis of the right obturator externus and was successfully treated with antimicrobials. This case demonstrates a rare case of streptococcal pyomyosits, in a temperate climate, without known predisposing factor or injury. We review the epidemiology of streptococcal pyomyositis in temperate climates and discuss the presentation of pyomyositis in children.